The first COVID-19 patient diagnosed in the United States—a young man in Snohomish county in Washington—was given remdesivir when his condition worsened; he improved the next day, according to a case report in The New England Journal of Medicine (NEJM). A Californian patient who received remdesivir—and who doctors thought might not survive—recovered as well.
Such evidence from individual cases doesn’t prove a drug is safe and effective. Still, from the drugs in the SOLIDARITY trial, “remdesivir has the best potential to be used in clinics” says Jiang Shibo of Fudan University, who has long worked on coronavirus therapeutics. Jiang particularly likes that high doses of the drug can likely be given without causing toxicities.
However, it may be much more potent if given early in an infection, like most other drugs, says Stanley Perlman, a coronavirus researcher at the University of Iowa. “What you really want to do is give a drug like that to people who walk in with mild symptoms,” he says. “And you can’t do that because it’s an [intravenous] drug, it’s expensive and 85 out of 100 people don’t need it.
Chloroquine and hydroxychloroquine At a press conference on Friday, President Donald Trump called chloroquine and hydroxychloroquine a “game changer.” “I feel good about it,” Trump said. His remarks have led to a rush in demand for the decades-old antimalarials. (“It reminds me a little bit of the toilet paper phenomenon and everybody’s running to the store,” Caplan says.) The WHO scientific panel designing SOLIDARITY had originally decided to leave the duo out of the trial, but had a change of heart at a meeting in Geneva on 13 March, because the drugs “received significant attention” in many countries, according to the report of a WHO working group that looked into the drugs’ potential. The widespread interested prompted “the need to examine emerging evidence to inform a decision on its potential role.” The available data are thin. The drugs work by decreasing the acidity in endosomes, compartments inside cells that they use to ingest outside material and that some viruses can coopt to enter a cell. But the main entryway for SARS-CoV-2 is a different one, using its so-called spike protein to attach to a receptor on the surface of human cells. Studies in cell culture have suggested chloroquines have some activity against SARS-CoV-2, but the doses needed are usually high—and could cause serious toxicities. Encouraging cell study results with chloroquines against two other viral diseases, dengue and chikungunya, didn’t pan out in people in randomized clinical trials. And nonhuman primates infected with chikungunya did worse when given chloroquine. “Researchers have tried this drug on virus after virus, and it never works out in humans. The dose needed is just too high,” says Susanne Herold, an expert on pulmonary infections at the University of Giessen. Results from COVID-19 patients are murky. Chinese researchers who report treating more than 100 patients with chloroquine touted its benefits in a letter in BioScience, but the data underlying the claim have not been published. All in all, more than 20 COVID-19 studies in China used chloroquine or hydroxychloroquine, WHO notes, but their results have been hard to come by. “WHO is engaging with Chinese colleagues at the mission in Geneva and have received assurances of improved collaboration; however, no data has been shared regarding the chloroquine studies.” Researchers in France have published a study in which they treated 20 COVID-19 patients with hydroxychloroquine. They concluded that the drug significantly reduced viral load in nasal swabs. But it was not a randomized controlled trial and it didn’t report clinical outcomes such as deaths. In guidance published on Friday, the U.S. Society of Critical Care Medicine said “there is insufficient evidence to issue a recommendation on the use of chloroquine or hydroxychloroquine in critically ill adults with COVID-19.” Hydroxychloroquine, in particular, might do more harm than good. The drug has a variety of side effects and can in rare cases harm the heart. Because people with heart conditions are at higher risk of severe COVID-19, that is a concern, says David Smith, an infectious disease physician at the University of California, San Diego. “This is a warning signal, but we still need to do the trial,” he says. What’s more, a rush to use the drug for COVID-19 might make it harder for the people who need it to treat their rheumatoid arthritis or malaria. Ritonavir/lopinavir This combination drug, sold under the brand name Kaletra, was approved in the United States in 2000 to treat HIV infections. Abbott Laboratories developed lopinavir specifically to inhibit the protease of HIV, an important enzyme that cleaves a long protein chain into peptides during the assembly of new viruses. Because lopinavir is quickly broken down in the human body by our own proteases, it is given with low levels of ritonavir, another protease inhibitor, that lets lopinavir persist longer. The combination can inhibit the protease of other viruses as well, specifically coronaviruses. It has shown efficacy in marmosets infected with the MERS virus, and has also been tested in SARS and MERS patients, though results from those trials are ambiguous. The first trial with COVD-19 was not encouraging, however. Doctors in Wuhan, China, gave 199 patients two pills of lopinavir/ritonavir twice a day plus standard care, or standard care alone. There was no significant difference between the groups, they reported in NEJM on 15 March. But the authors caution that patients were very ill—more than one-fifth of them died—and so the treatment may have been given too late to help. Although the drug is generally safe it may interact with drugs usually given to severely ill patients, and doctors have warned it could cause significant liver damage. Ritonavir/lopinavir and interferon-beta SOLIDARITY will also have an arm that combines the two antivirals with interferon-beta, a molecule involved in regulating inflammation in the body that has also shown an effect in marmosets infected with MERS. A combination of the three drugs is now being tested in MERS patients in Saudi Arabia in the first randomized controlled trial for that disease. But the use of interferon-beta on patients with severe COVID-19 might be risky, Herold says. “If it is given late in the disease it could easily lead to worse tissue damage instead of helping patients,” she cautions. Thousands of patients The design of the SOLIDARITY trial can change at any time. A global data safety monitoring board will look at interim results at regular intervals and decide whether any member of the quartet has a clear effect, or whether one can be dropped because it clearly does not. Several other drugs, including the influenza drug favipiravir, produced by Japan’s Toyama Chemical, may be added to the trial. To get robust results from the study, several thousands of patients will likely have to be recruited, Henao Restrepo says. Argentina, Iran, South Africa, and several other non-European countries have already signed up. WHO is also hoping to do a prevention trial to test drugs that might protect health care workers from infection, using the same basic protocol, Henao Restrepo says. The trial’s European counterpart, Discovery, will recruit patients from France, Spain, the United Kingdom, Germany, and the Benelux countries, according to an INSERM press release today. The trial will be led Florence Ader, an infectious diseases researcher at the University Hospital Center in Lyon. Doing rigorous clinical research during an outbreak is always a challenge, Henao Restrepo says, but it’s the best way to make headway against the virus: “It will be important to get answers quickly, to try to find out what works and what doesn’t work. We think that randomized evidence is the best way to do that.” *Correction, 27 March, 6:50 p.m.: Ana Maria Henao Restrepo's role at WHO has been updated.
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